Data base languages, in particular DDL, development at CODASYL

ABSTRACT

Since the publication, in April, 1971, of the Data Base Task Group(DBTG) report(ref.1) to the CODASYL Programming Language (&equil;COBOL) Committee(PLC) several committees and task groups of the CODASYL organization have enhanced and improved the languages and specifications proposed by DBTG. Two recent publications by CODASYL, the CODASYL Data Description Language Journal of Development (DDL-JOD - see ref.2) and the CODASYL Data Base Languages Proposal (DBLTG-73001 - see ref.3), which together constitute a complete revision of the DBTG report reflect this further development. This paper briefly summarises the DBTG, report and then describes the more significant (in the author's opinion) changes made to the Schema DDL documented in the DDL-JOD. The changes to the Subschema DDL and the DML, suggested in DBLTG-73001 are more briefly summarized mainly because the PLC Has recently approved many further changes to this proposal. Certain changes to the Schema DDL approved since the decision to publish the DDL-JOD was taken in April, 1973, are also indicated.

REFERENCES

• 1: Data Base Task Group Report to the CODASYL Programming Committee, April 1971. - available in Europe from both the British Computer Society and from the IFIPS Administrative Group (IAG) in Amsterdam.
• 2: The Codasyl Journal of DDL Development. - the first edition is now available in Europe from the BCS and IAG. From the BCS at 29 Portland Place, London, the journal costs £3.00 to non-members a £2.55 to members. In USA it is published as NBS handbook 113 price $1.70 from the Government Printing office (but reference SD catalogue C13.6/2:113).
• 3: The Codasyl Journal of COBOL Development. - This document is published approximately every two years - the latest edition published in January 1973 costs $3.50 from Technical Services Branch, Department of Supply and Services, 88 Metcalf Street, 5th Floor, Ottawa, Ontario, Canada KIA 025 (Cheques to be made payable to the 'Receiver General of Canada')
• 4: The COBOL Data Base Proposal (DBLTG-73001). This document is available from the address above for $2.50.

INDEX TERMS

Primary Classification:
  H. Information Systems
  H.2 DATABASE MANAGEMENT
      H.2.4 Systems

          Nouns: CODASYL

Additional Classification:
  H. Information Systems
  H.2 DATABASE MANAGEMENT
      H.2.1 Logical Design
          Subjects: Schema and subschema

General Terms:
Design, Languages